1. Field of the Invention
The present invention relates to a virtual memory control management system for performing demand paging and, more particularly, to a virtual memory control management system for registering a virtual page to which a real page is allocated to execute a task.
2. Description of the Related Art
As shown in FIG. 1, a conventional system of this type includes working set 10 for each execution unit called a task (or a process) to register (page-in) a virtual page which is necessary during execution in this working set, and allocates a real page to the virtual page. This system is based on the assumption that a program has a locality. However, in virtual spaces which are necessary for the program executed as one task, the locality may or may not be present in accordance with the utilization form of virtual pages. That is, in many cases, as shown in FIG. 2, in sections including a code section, a data section, a stack, and the like, although the code section has a locality, the data section has no locality. Therefore, as shown in FIG. 1, when the task is executed using virtual pages of code section, data section, or stack virtual space 11, 12, or 13, the number of page-in operations of virtual pages in data section virtual space 12 is greatly increased. As a result, the virtual pages of the code section having a locality are flashed (page-out) from working set 10 due mainly to a nonlocality of the data section, thus degrading execution speed of the programs.